Coherent optical communication has attracted renewed interest in recent years. In coherent optical communication, an incoming optical signal is combined with a local oscillator signal to generate an interference signal that can be used to detect the data contained in the incoming data signal.
In order for the two signals to properly interfere or “beat,” the two signals must be coherent, i.e., have the same frequency, phase, and polarization. In order to produce a coherent local oscillator signal, the phase and polarization of the optical carrier of the incoming optical signal must be recovered. Unfortunately, carrier phase and polarization recovery remains a significant challenge of coherent optical communication. As a result, coherent optical communication is not frequently used.
Although various methods have been proposed for determining the phase and polarization of the optical carrier of incoming signals, such methods have proven to be complex and/or unreliable. Moreover, known methods are incapable of simultaneous recovery of both phase and polarization, further increasing complexity. Therefore, it can be appreciated that it would be desirable to have less complex and/or more reliable systems and methods for optical carrier phase and polarization recovery.